Module 5 Genetic Influences on Behavior JONATHAN C. LEE AP PSYCHOLOGY

Charles Darwin First evolutionary psychologist. Think of deep time. Spans in millions of years.

Creationism vs. Evolution

Challenges of Evolution  Why does change take place?  How do new species emerge?  What are the functions of parts? Think about it: You came from a long line of ancestors, if your ancestors from a million years ago did not reproduce, you would not exist today! 1A. Explained change over time: descent with modification. 2A. Explained the apparent purpose quality of component parts: adaptive function. 3A. United all species into one grand tree of descent: including humans.

Does our genes determine our behavior?  Chromosomes: Threadlike structures made of DNA molecules contain the genes.  DNA: (deoxyribonucleic acid) a complex molecule containing the genetic information that makes up the chromosomes.  Genes: The biochemical units of heredity that make up the chromosomes; a segment of DNA capable of synthesizing protein.  Genome: The complete instructions for making an organism, consisting of all the genetic material in its chromosomes.

Going into our Biological Blueprint  Each human has 23 chromosomes from the mother and 23 (egg) chromosomes from the father (sperm) for a total of 46 chromosomes.  There are about 30,000 genes in each of us.  Each gene has 4 alphabet of life (A,T,C, G), composed of nucleotides.  The smallest human chromosome Y has 50 million nucleotide letters and the largest has 250 million nucleotide letters.  Collectively there are about 3.1 billion paired nucleotides that define the genes that you carry. *ATCG = adenine-thymine, cytosine-guanine

Human traits are influenced by gene complexes – many genes acting in concert  Human genome researchers have discovered the common sequence of the 3.1 billion letters within the human DNA.

How do we use natural selection to explain behavioral tendencies?  Belayev worked with 30 male and 100 female foxes. 40 years they bred the fox to become extremely docile and well-behaved.  Belyaev demonstrated when certain traits are selected, those traits over time, can prevail.  Is it ethical to pick traits of your unborn fetus (i.e. blue eyes)?  Natural selection: the principle that, among the range of inherited trait variations, those that lead to increased reproduction and survival will most likely be passed on to succeeding generations.  Mutations: a random error in gene replication that leads to a change in the sequence of nucelotides; the source of all genetic diversity.

Evolutionary Psychology

Questions to consider  Come up with answers in your group in the next five minutes.  P. 101

Sexuality  What do you think about this statement: Men pair widely but women pair wisely? (p. 103)  Gender: in psychology, the characteristics, whether biologically or socially influenced, by which people define male and female.

Twins  Identical twins: twins who develop from a single fertilized egg that splits into two, creating two genetically identical organisms.  Fraternal twins: twins who develop from separate eggs. They are genetically no closer than brothers and sisters, but they share a fetal environment. Raise your hands if you are a fraternal twin!!

Temperament & Heritability  Temperament: A person’s characteristic emotional reactivity and intensity.  Heritability: the proportion of variation among individuals that we can attribute to genes. The heritability of a trait may vary, depending on the range of populations and environments studied.

Criticisms of Evolutionary Psychology  People are not “hard-wired”  Excluded cultural factors and environmental factors that also makes us human.  Challenges Judeo-Christian beliefs